The present invention relates to a cooking device with at least one gas burner and a flat, plate-like molded body providing a cooking device surface surrounding the at least one gas burner. The molded body is made from a glass-ceramic material or another heat-resistant material with a low thermal expansion coefficient, such as a special glass or ceramic material. The cooking device surface covers the cooking device. Components or operating parts of each gas burner are arranged in the vicinity of an opening provided in the molded body assigned to the respective burner under, over or in the principal plane of the molded body and the gas burners are supported by the molded body.
Gas or gas/electric ranges, the so-called mixed range with a glass-ceramic cooking device surface have been on the market for several years. These cooking units are operated with atmospheric gas burners, as found in the most common design in standard stainless steel or steel cooking units for many years.
Gas ranges with glass-ceramic cooking device surfaces are widely used particularly because of the aesthetic features and ease of cleaning of the glass-ceramic surface, which, e.g. can also be used as a work surface. The incorporation of a metallic gas burner in the currently known design of this type has been found to be disadvantageous because of these consumer motivations. The entire appearance of the cooking apparatus and especially the ability to clean it is poor in the area where the atmospheric gas burner is connected with the gas-ceramic cooking device surface. Furthermore often very expensive connection techniques are required for incorporation of the gas burner, so that the burner is unobjectionable and is connected with the glass-ceramic cooking device surface in a liquid-tight manner. The known assembly systems are very time consuming and expensive.
A burner apparatus is described in European Patent EP 0 536 619 B1, which is known for use with cooking devices, in which at least one gas burner is mounted in a supporting frame and the surrounding surface around the gas burner or gas burners is covered by means of a molded body made from a brittle material, such as glass, glass-ceramic or ceramic material. Each gas burner in this apparatus extends through an opening in the molded body made of brittle material until above its surface. The gas burner or burners is or are supported by the molded body made from the brittle material and a permanent elastic, flexible connecting and sealing device is arranged between the molded body and each gas burner. This connecting and sealing device has a solid and fluid-tight connecting and sealing element engaging on at least one connecting surface of the gas burner and on an edge region of the opening in the molded body for mounting and at the same time providing a liquid-tight seal of the gas burner in the opening of the molded body for mounting and sealing the gas burner in the opening in the molded body. Securing and retaining devices are provided between the gas burner or burners and the supporting frame, which are operative when the supporting molded body is absent, permitting limited movement related to screw attachment and retaining.
In the gas ranges or cooking devices with burners currently on the market the plate covering the area surrounding the gas burner is provided with substantially larger openings than are required for the respective individual gas burners. The comparatively wide annular gap between the gas burner and the opening edge must be effectively covered. The resulting seal is only partially successful and is insufficient. Overflowing cooking materials can penetrate between the plate and the gas burner. Frequent cleaning of this device is thus required which often requires partial disassembly.
International Patent Application PCT WO 97/00407 describes a plate for a gas range made from a glass-ceramic material, which has at least one opening for a gas burner and several convex elements, which are distributed around this opening and operate as supporting elements for a cooking vessel, such as a pot, which is to be heated with the help of the burners. The convex elements are themselves essentially parts of the plate.
In the unit described in WO 97/00407 the supporting grate, the so-called pot support, in the transitional region of the gas range around the burners with the open flame to the glass-ceramic plate, which is required with conventional gas ranges with open gas burners, may be omitted. For this purpose according to this WO application several equal height convex portions are distributed around the opening of the burner in the glass-ceramic plate and project above the burner acting as a support for a cooking vessel. They are formed in one-piece with the glass-ceramic plate.
In German Patent DE 43 33 334 C2 a plate made from a glass-ceramic material is provided as a component of the cooking apparatus, in which at least one region of the one-piece plate projects or extends from the main plane of the plate in the form of a truncated conical portion, spherical segment portion or truncated spherical portion, or prismatic portion, tetrahedral portion, pyramidal portion, truncated prismatic portion, truncated tetrahedral portion or truncated pyramidal portion. The principal plane of the one-piece plate can have passages and mounting openings for the gas burner. The purpose of the invention disclosed in DE 43 33 334 C2 is a new operational embodiment of a glass-ceramic plate operating as a cooking field, which can be easily assembled without greatly changing the existing structures and the requirements for additional frame and attachment parts is minimized. DE 43 33 334 C2 does not describe the structure of a specific burner arrangement for a cooking apparatus with gas burners.